- During this Ascension weekend, many French women plan to take advantage of the summer temperatures by going to the beaches of the coast that have reopened, which raises the question of the risk of contracting the coronavirus while swimming.
- The French Research Institute for the Exploitation of the Sea (Ifremer) published this week the results of analyzes carried out on samples of sea water taken from the French coast, and the first results are reassuring.
- The High Council for Public Health recalls that the main risk of contamination is by droplets, hence the importance of respecting barrier gestures and social distancing.
After two months confined to the house like lions in cages, many dream of only one thing: treading the sand of the beaches and going for a dip in the waves. For some of those who live near the coast, this is already possible. Almost everywhere on the Atlantic and Mediterranean coasts, several cities have reopened their beaches for walking and swimming, and others will follow suit as of this Ascension weekend, during which the temperatures are expected summer.
The sun and the sea should not however make us forget that the coronavirus remains present on the territory. The epidemic continues, new sources of contamination have been identified and no vaccine is currently available to protect against it. But while traces of SARS-CoV2 have been found in wastewater samples, the question arises as to whether one could contract the coronavirus by bathing in seawater. In this case, the vacation scenario summer would take lead seriously. According to initial research conducted on the subject by the French Research Institute for the Exploitation of the Sea (Ifremer), there would be no worries to be had.
No traces of coronavirus in seawater samples
Since the appearance of Covid-19, several scientific studies have noted the presence of the virus in the stools of infected patients. From toilets to sewers and sewage treatment plants, there is only one step taken by several research groups which quickly found elements of the genome of SARS-CoV-2 in the wastewater of many large cities. of the planet, including Paris. No risk of contamination of tap water, subjected to scrupulous treatment.
Certainly, the presence of traces of the virus in the stool does not necessarily mean that it is infectious or transmissible by this route, say some experts, who recall that it is unable to replicate in nature outside a host. But after the detection of SARS-CoV-2 in wastewater, Ifremer decided to carry out analyzes to verify that this virus was not present in seawater or in the shellfish of the French coast. The institute therefore took four samples of marine water potentially subject to human discharge. And none have shown traces of SARS-CoV-2. "Even if it is not worth certainty for all shellfish and metropolitan marine waters, the absence of traces of SARS-CoV-2 revealed by our study is good news," said Soizick Le Guyader, virologist and head of Nantes environment health and microbiology laboratory from Ifremer.
Closely monitor the quality of bathing water
But "proving the real absence of the virus is a difficult art," notes the researcher. And the samples were taken during confinement. “We have therefore decided to continue our samples and analyzes on the same sites every two weeks for another several months, in order to monitor the possible effects of a potentially increased circulation of the virus in the population in the context of the gradual lifting of containment measures ”. Samples which will be practiced in particular on waste water likely to be discharged near the coast.
Referred by the Ministry of Health, the High Council for Public Health (HCSP) spoke in an opinion given in early May on the risk of contracting Covid-19 while bathing on the beaches of the coast. The HCSP indicates that "the analysis of the scientific literature does not confirm, to date, the presence of infectious SARS-CoV-2 in the waters of the natural environment". But after the discovery of traces of the virus in wastewater, the HCSP "recommends paying particular attention, during the deconfinement phase, by increasing the frequency of monitoring the quality of bathing water in terms of faecal contamination with, if necessary, early closure measures for sites known to be degraded during rainy episodes. He advises against swimming on sites that are not subject to regulatory health control ”.
Spain has also looked into the matter. A study by the Higher Council for Scientific Research in Spain concludes that "although there are currently no data on the persistence of SARS-CoV-2 in seawater, the dilution effect, as well as the presence of salt, are factors that may contribute to a decrease in viral load and its inactivation, by analogy with similar viruses. ” The salinity of seawater is therefore an element likely to deteriorate the envelope of the coronavirus.
Lack of social distancing: the source of the risk
This does not mean zero risk. And with the summer holidays fast approaching, many are waiting for a clear answer on the risk of catching the Covid-19 while bathing in sea water. For the HCSP, responsible for lighting the Minister of Health, the possible link between Covid-19 and swimming is mainly due to non-compliance with barrier gestures. The body recalls that "it is the strict respect of physical distancing measures which constitutes a fundamental and priority element of general prevention of infection by SARS-CoV-2".
By this summer, "the regional health agencies should certainly issue recommendations to make bathing on the coast safer with regard to the risk of SARS-CoV2", advances the Ifremer. And since, as health authorities recall, “the main route of transmission of SARS-CoV-2 in beaches, rivers, lakes and swimming pools is through respiratory secretions generated by coughing, sneezing and contact with person to person ”, respect for social distancing will be a major protection tool, on sand as in water. But the task looks already complicated. Just reopened, quickly crowded beaches in Morbihan have already been closed for non-compliance with barrier gestures and incivility.
Society
Deconfinement in Brittany: Crowds, insults and non-respect ... The municipalities close their beaches
Society
Deconfinement in the Bouches-du-Rhône: Fifteen beaches reopen on Thursday
- Health